Method and apparatus for equalizing pressures of, or purging, the fluid contents of a conduit



Sept. 5, 1939. T. A. LARRY El AL 2,171,576

METHOD AND APPARATUS FOR EQUALIZING PRESSURES OF OR PURGING, THE FLUIDCONTENTS OF A CONDUIT Filed NOV. 19, 1936 2 Sheets-Sheet l.

Z I a V 0 Z J Z5 J4 ll .14 j

gvwmvtow Sept. 5, 1939. T. A. LARRY El AL 2,171,575 METHOD AND APPARATUSFOR EQUALIZING PRESSURES OF,

OR PURGING, THE FLUID CONTENTS OF A CONDUIT Filed Nov. 19, 1936- 2Sheets- Sheet 2 MIW . dilute the contents of the conduit.

Patented Sept. 5, 1939 UNi'lED STATES PATENT OFFIQE.

METHOD AND APPARATUS FOR EQUALIZ- ING PRESSURES OF, OR PURGING, THEFLUID CONTENTS OF A CONDUIT Application November 19, 1936, Serial No.111,744

5 Claims.

This invention relates to methods and apparatus for use in themaintenance repair of pipe line systems such as are generally employedfor the distribution of gas or other fluids.

In the maintenance and repair of such systems it is frequently necessaryto replace and rep-air a section of a fluid containing conduit and it iscustomary to temporarily isolate such a section from the remainder ofthe conduit during such replacement or repair.

It will be apparent that where a section of a conduit, containing afluid under high pressure, is removed, a large amount of fluid willescape during the cutting operation. One of the objects of thisinvention is to provide a method and apparatus for permitting the fluidto flow out of the section and to conduct the fluid to a pointrelatively remote from the conduit where it may be released in acontrolled manner.

A further object of the invention is to provide a method and apparatusfor effecting the complete removal of any combustible or noxious gasesfrom the section which is to be removed.

It will be understood, that after the section has :been replaced orrepaired, air will have accumulated within the section. After flow isrestored through the section the air may travel through the conduit as abubble, and in any event it will A further and important object of thisinvention is to provide a method and apparatus whereby the air may bepurged from the section which has been replaced or repaired, and wherebya fluid, similar to that which is contained in the remainder of theconduit may be substituted for the air.

Other objects of the invention will be apparent from the accompanyingdescription and drawings.

Referring to the drawings:

Figure l is a vertical elevation, partly in section, showing theapparatus of this invention applied to a conduit.

Figure 2 is a view, partly in section of one form of apparatus which maybe used to establish an opening in the conduit.

Figure 3 is a View, partly in section, of one form of apparatus adaptedto provide communication with the interior of the section which is to bereplaced or repaired and to prevent the flow of fluid into the sectionfrom the conduit.

Figure 4 is a horizontal section taken on the line 44 of Figure 3.

Referring more particularly to the drawings, Figure 1 shows apparatus,which may be used in practicing this invention, applied to a pipe lineor conduit it, it being assumed that the pipe line is tied in at bothends to sources of fluid under pressure, and that the intermediatesection H is to be removed and replaced by a new section. ,Since theconduit is connected to a source of fluid at either side of the sectionII, the arrows indicating the direction in which the fluid would flow ifan outlet were afforded in the section, it will be understood that thesection i i may be isolated from the remainder of the conduit withoutinter-- rupting service to consumers whose service are connected to theconduit at either side of the section.

As shown. in Figure l, shut-ofi apparatus, generally designated at E2and I3, are attached to the conduit it! at either side of the section itfor the purpose of isolating the section 23 from the remainder of theconduit. As illustrating one form of apparatus which may be used incarrying out this invention, the detail construction of the two shut-01fapparatus l2 and 13, which are generally similar, and the preferredmanner of attaching the shut-off apparatus to the conduit, Will bedescribed below.

The apparatus includes a fitting generally designated by the numeral Mwhich may be formed as an integral casting, and thereafter divided intotwo parts, by cutting along the two sides. The fitting may consist of asubstantially cylindrical or tubular body, having an opening at itsupper end and closed at its lower end. The upper end, as shown in Figure3, is preferably threaded exteriorly for the attachment of other partsof the shut-off apparatus.

The fitting is provided with aligned lateral openings, which are adaptedto receive a pipe, and the lower cylindrical portion is providedinteriorly with a circumferential ledge or projection 23 which isadapted to serve as an abutment to limit the inward or downward movementof the shutoff member which, as will be described, is inserted throughthe open end of the fitting.

As shown in Figure 1, a fitting M is secured to the conduit at eitherside of the section i! which is to be removed. After the fitting is cuttransversely and separated into two parts the upper and the lower partsare brought together around the pipe and welded to each other bytransverse welds 24, 24 and the fitting is then Welded to the pipe bythe end welds 25, 25.

After the fittings have been welded to the conduit at spaced points, oneither side of the section H, a valve body 26 having a tapered Valveseat 27 and provided with a gate valve iii operable by a handle 29, asshown in Figures 1 and 2, is threaded on the upper end of each. fitting.

An adapter sleeve is threaded into the upper end of each valve body 25,as shown in Figure and a device or machine, generally similar to pipedrilling machines of well known construction and including the feedsleeve Si, is positioned upon each adapter sleeve 36 by means of screwthreaded engagement between the feed sleeve 3i and the upper end of theadapter sleeve 39.

Bar 32 is slidably and rotatably mounted within the feed sleeve 3|, afluid-tight joint being maintained between the two by means ofconventional packing (not shown) secured upon the upper end of the feedsleeve 3| by an internally flanged collar 33. The bar 32 is provided atits upper end with an operating handle 35 having a conventional ratchetdevice thereon to permit the bar to be rotated with a. ratchet efiect. Acollar 35 is fixed on the upper portion of the bar 32 beneath the handle34 and, in order that the bar 32 may be fed downwardly in the usualmanner, a feed screw 36 is threaded upon the feed sleeve 39 and may beconnected to the bar 32 by means of a yoke 31 pivoted upon the feedscrew and having its head portion slotted as at 33 so that it may bemoved into engagement with the upper surface of the collar 35 as shownin Figure 2.

The lower end of the bar 32 is provided with a central bore 39 forreception of a pilot drill Ml, which is retained therein by means of apin 4! passing through suitable apertures in the bar and pilot drill.The lower end of the pilot drill is enlarged to provide the shoulder 42thereon.

The lower end of the bar 32 is externally threaded for engagement withthe internal threads of a shell cutter 43, and is provided with a flange44 positioned above the screw threads, against which the upper end ofthe shell cutter abuts when the latter is tightly screwed onto the bar.

In order to drill through the pipe it, within the fitting l4, the bar 32is moved downwardly,

with the gate valve 28 open, until the pilot drill Mi engages theconduit. The yoke 3? is then swung into engagement with the bar 32, itsslotted head portion positioned above the collar 3-5 of the bar, and thedrilling accomplished by rotating the bar 32 by means of handle 34 andapplying downward pressure by rotating the feed screw 36 to theright.

The diameter of the shell cutter 43 is preferably slightly greater thanthe internal diameter of the conduit iii in order that substantially theentire cross section of the pipe will be removed as shown in Figures 2and 3. It will be understood that the pilot drill precedes the shellcutter through the conduit and acts as a guide for the shell cutter. outof the pipe by the shell cutter, will be caught on the shoulder 42 atthe lower end of the pilot drill MB and will be removed from the fittingwhen the drill is withdrawn.

Owing to the fact that the drilling device is completely enclosed, nofluid will escape during the drilling operation.

When the drilling is completed, the yoke 31' is disengaged from the bar32 and the latter is then raised to withdraw the shell cutter and pilotdrill into the adapter 39. 28 is now operated to closed position and thedrilling apparatus 35 is removed by unscrewing the adapter 38 from thevalve body 26.

Although, as described above, a drilling apparatus may be attached toeach valve body 23 and the two openings established simultaneously, itmay, in some instances, be preferable to use one drilling apparatuswhich is attached successively to the valve bodies 26 on the respectivefitting.

Shut-01f apparatus 12 and I3 are now secured to the upper end of thevalve bodies 26, as shown in Figure 1.

Referring more particularly to Figure 3, each The coupons, which are cutThe gate valve shut-off apparatus includes an adapter 45, externallyscrew threaded at its lower end for attachment to the upper end of thevalve body 26. The adapter, which may be made in various sizes, ispreferably provided at its upper end with internal screw threads for theattachment of a substantially cylindrical chamber The lower open end ofthe chamber 46 is externally screw threaded for engagement with internalscrew threads at the upper end of the adapter 35, an annular gasket 31being inserted between the two to provide a fluid-tight joint. Thechamber 46 is provided with an apertured top wall 48 and the side wallof the chamber is provided with an internally threaded opening 9. Theside wall of the chamber 36 extends above the top wall 48 and isprovided, at its up- 7 per extremity, with internal threads for theattachment of a feed sleeve 50.

A bar 55 is slidably and rotatably mounted Within the feed sleeve 50 andwithin the centrally apertured top wall 38 of the chamber 46, a tightjoint being maintained around the lower end of the feed sleeve, by meansof a conventional packing 52 located between the feed sleeve 50 and theupper wall 33 of the chamber 46.

The bar 5i is provided at its upper end with an operating handle 53.Spaced collars 54 and 5 5 are fixed on the upper portion of the bar 5|and in order that the bar 5i may be forced upwardly or downwardly, afeed screw 58 is threaded on the feed sleeve 50 and may be connectedwith the bar 51! by means of a yoke 57 pivoted upon the feed screw 56and having its head portion slotted as at 58 so that it may be swunginto engagement with the bar 5! between the collars 5i; and 55.

The lower end of the bar 5! is provided with a socket 59, and a lowercounter-bored socket 6t internally threaded with right hand threads. Thelower end of the bar Si is slightly enlarged to provide a shoulder 85for the retention of a sleeve 62, the upper end of which is internallyflanged at 63. The sleeve 62, which is adapted to be slipped on over thetop of the bar 5i, during the assembly thereof and before the handle 53and collars E i and 55 are attached, extends below the lower extremityof the bar 5! and is provided at its lower end with internal screwthreads for the attachment of a shut off means to be described below.

The shut-off means, which is attached to the lower end of the bar 5!,may include a substantially cylindrical member 64, preferably made ofsome resilient material such as rubber and having a diameter which ispreferably slightly smaller than the diameter of the above mentionedshell cutter. The member 54 is partially cut away at one side as isshown at 65, and the cut away portion preferably extends from a pointapproximately half-way down its side upwardly and inwardly to the top ofthe member. Disc-like caps 65 and 651, which are preferably inwardlyflanged, as shown at 68 and 6%, are positioned above and below themember 64. The caps 86 and 6; and the member 64 are centrally aperturedfor the reception of a rod '56 on which they are slidably mounted. Therod H3 is provided at its upper end with a slightly enlarged head H andits lower end is threaded for the reception of a nut E2 whereby themember 64 may be clamped between the upper and lower caps 66 and 61 whenthe nut 12 is tightened. The nut 72 is preferably provided with slotsupon its undersurface and the rod NJ is I shut-01f apparatus aperturedat its lower end for the reception of a conventional locking pin 13. Theupper cap 61 is cut away at one side as at 14 to conform with the cutaway portion 65 of the member 64, and the flange 59 follows the contourof the cut away portion, in order to prevent rotation of the member fitwith respect to the cap 6'! after the parts are assembled. The cap 61 isprovided with a central and upwardly extending cylindrical portion 75which is externally threaded for attachment to the internally threadedsleeve 62.

When the cylindrical portion 15 of the cap 67 is threaded into thesleeve 52 it will abut the lower end of the bar 5| and it will,therefore, be apparent that downward pressure on the bar 5| will bedirectly transmitted to the cap 61. It will also be apparent that upwardmovement of the bar 5i will raise the cap 5'! by reason of the fact thatthe internally flanged sleeve 62 engages the lower enlarged end of thebar 5| and also engages the upwardly extending central portion 15 of thecap 87,

The lower extremity of the bar 5 I, which forms the socket 55, isprovided with slots l6, 15 adapted to receive lugs ll, l1 positioned onthe upper surface of the cylindrical portion l5, as shown in Figure 4,whereby relative rotation of the cap 6? and consequently the member 54,with respect to the bar 5!, will be prevented.

In carrying out the method of the present inyen-tion, a shut-ofiapparatus, such as is above described, is connected to each of the valvebodies 25 on the respective fittings l4, it being understood that thefittings are located at either side of the section II, which is to beisolated from the conduit ill, as shown in Figure 1.

.As above described, each of the chambers 45, of the shut-off apparatus,is provided with an aperture 35 in its lateral wall. A pipe 18 providedwith a valve 19, is connected to the shut-01f apparatus i2 (Figure 1) atthe aperture 49 and a plug 85 is threaded into the aperture 49 of theshut-off apparatus Hi.

When the shut-off apparatus is attached to the upper end of the valvebody 25 the member 64 will be withdrawn into a position within thechamber 56. This withdrawal is accomplished by disengaging the yoke 5'!from the bar 5| and pulling up on the handle 53. The diameter of themember 54 is substantially less than the internal diameter of thechamber 45, the adapter and the valve body, so that when the member 64is in raised position it will not prevent the flow of fluid from theconduit ill into the upper part "of the chamber 45.

After a shut-off apparatus has been attached to each of the valve bodies25 and after the valve it on the shut-01f apparatus !2 has been closedand after the plug Bil has been inserted in the l3, the valves 28 may bemoved to open position.

By turning the handles 53 of the respective shut-off apparatus, members64 are rotated until the cut away portions 65 are aligned with the axisof the conduit H3 and face toward each other.

The bar 5! of the shut-ofi apparatus i3 is then moved downwardly, bypushing down on handle 53 until the member 64 is in the position shownin Figure 3, the downward movement being arl", rested when the lower cap55 contacts the inwardly projecting abutment 23 of the fitting M.

The yoke 5? of the shut-01f apparatus [3 is new swung to uprightposition engaging the bar 5i between the collars 54 and 55 as shown inFigure 3, and feed screw 56 is turned to the right to apply downwardpressure, through the collar 62 and bar 5| to the cap 61.

The cap 66 at the lower end of the member 64 is held against downwardmovement by the abutment 23 of the fitting l4, and, since the member 64is made of resilient material, the downward pressure on the cap 5'! willcause the member 6 3 to expand laterally as shown in Figure 1.

Upon expansion of the member 64, it will be forced into contact with theadjacent walls of the conduit H], as shown in Figure 1, and act as avalve to prevent flow of fluid from the conduit into one end of thesection I I.

The member 64 of the shut-oil apparatus I2 having been adjusted as abovedescribed so that its cut away portion faces toward the shut-offapparatus 53, it is now compressed in the same manner as described inconnection with the shutoff apparatus 13. As a result, the flow of fluidfrom the conduit ill into the other end of section I I will be shut offand the section I I will thus be isolated from the conduit Hi.

It will be apparent that fluid which may be under high pressure will betrapped within section ll. Since this fluid may be highly combustible ornoxious, it is frequently desirable to remove it from the section l land conduct it to a relatively remote point where it may be safelyliberated, particularly so where the operations on the section H are tobe carried out in a trench and where acetylene torches are to be used incutting the section I l. A relatively remote point may be considered tobe about two feet or more from the main conduit. This may frequently beaccomplished by merely opening the valve 19 and permitting the fluid toflow out of the section ll through the cut away portion 55 (shut-offapparatus l2) and thence through the chamber 46 and pipe #8, whichlatter may extend upwardly for a considerable distance. Where it isnecessary to remove all traces of the original gaseous contents of thesection 1 l, or where the section contains a liquid, the plug 89 may beremoved from the shut-off apparatus l3 and a source of compressed air(not shown) may be attached at the aperture 49. Compressed air is thenallowed to enter the chamber 45 and will pass downwardly into thesection H through the cut away portion 65 of the member 86 and thenthrough the section II and out through the pipe 18 connected to theshut-off apparatus l2, thus completely purging section I I.

After the replacement or repair of section II is completed and it isdesired to restore flow therethrough, the members 64 of the respectiveshut-off apparatus may be removed, as will be hereinafter described, butin order that the contents of the conduit Hi shall not be diluted withthe air now contained in the section I l, the latter is first purged inthe following manner.

By turning the handle 56 to the left, downward pressure on the member ofthe shut-ofl apparatus 53 may be relaxed Thereupon the member 65 willassume its original cylindrical form and fluid will be allowed to passfrom the conduit ill into the section l If, at the same time, the valve19 is opened, the fluid coming from the conduit it! into the section IIwill force air contained in the latter out through the shut-01fapparatus l2 and pipe 78. When the fluid from the conduit l9 reaches theoutlet of the pipe 18, in its original concentration, the valve 19 willbe closed and the shut-off apparatus may be removed as will be describedhereinafter.

In actual practice a certain amount of air may remain in the chamber 46of the shut-off apparatus it unless the flow of fluid through thesection i i is permitted for a considerable period, but

- since the valves 28 in the valve bodies 25 are sub sequently closed,as will be explained, this air will not mix to any extent with thecontents of the conduit is. However, if it is necessary to remove theair from the chamber it: of the shut-off apparatus iii in an expeditiousmanner, the plug 80 may be removed while the fluid from the conduit I9is being permitted to enter the section l I.

In some cases the pressure in the conduit l may be much greater than thepressure in the secytion IE and if the material of member 64 is notsufficiently resilient to return to its original cylindrical shape, flowmay be established into the section l by turning the handle 53 throughan angle of 90. The cut away portion 65 will then provide :communicatienbetween the conduit Ill and the section i l, and no difliculty will beexperienced in raising the member 94 after pressures have been thusequalized.

Although the above method of purging air from the section It ispreferred, it may in some cases be desirable to connect a source offluid, which fluid is similar to that contained in the conduit I8, tothe aperture ii-3 of one of the shut-off apparatus and force the fluidthrough the section I l and out Zthrough the aperture 49 of the othershut-off apparatus.

When the section I! has been replaced or repaired and when the aircontained therein has been replaced by fluid from the conduit ID, as

above explained, the shut-ofi apparatus [2 and I3 and the valve bodies26 may be removed from the fitting i iand the upper openings of thelatter may be closed without substantial loss of fluid.

he feed screws 56 having been turned to the left to r lax pressure onthe members 64, the yokes 5'! may be disengaged from the bars 5 I, andthe members E iare drawn up into the chambers 16 by pulling up on thehandles 53. The gate valves 25 are then closed, to prevent further flowof fluid into the chambers 46 and the latter may be unscrewed andremoved from the adapters 45. If it is not convenient or desirabletoutilize the valve bodies 26 and the valves 28 as closures for the openends of the fittings M for an indefinite period of time, a plug likeclosure may be inserted in the open end of each fitting as described inour ccpending application Serial No. 100,780, filed September 14, 1936.

Matter described but not claimed herein is claimed in our copendingapplications Serial No.

16%,782, filed September 14, 1936; and Serial No. 122,248, filed January25, 1937; and in the copending application of Timothy Allan Larry, EarlE. Cline, and Orville J. Hawkins, Serial No.

123,284, filed February 27, 1937. 7

Since the above apparatus and methods may be modified without departingfrom the scope of the invention, it is intended that all mattercontained in the above description and shown in the accompan-yingdrawings, shall be regarded as merely illustrative.

We claim:

1.. The method of isolating a section of a fluid containing conduit,whereby the section may be replaced or repaired, and subsequentlyre-establishing communication between the section and the remainder ofthe conduit without substantial dilution of the fluid in the conduit,which comprises establishing openings at either side of the section,inserting valve members in the conduit through the openings to preventflow of fluid into the section, and after the section has been replacedor repaired, displacing the air from the section, and from the conduit,by permitting the fluid contents of the conduit to enter the section.

2. The method of isolating a section of a fluid containing conduit,whereby the section may be replaced or repaired, and subsequentlyre-establishing communication between the section and the remainder ofthe conduit Without substantial dilution of the fluid in the conduit,which comprises establishing openings at either side of the section,inserting valve members in the conduit through the openings to preventflow of fluid into the section, and after the section has been replaceder repaired, providing an outlet through one of said openings for theair which is trapped in the section and displacing the air from thesection, and from the conduit, by permitting the fluid contents of theconduit to enter the section.

3. The method of isolating a section of a fluid containing conduit,whereby the section may be replaced or repaired, and subsequentlyre-establishing communication between the section and the remainder ofthe conduit without substantial dilution of the fluid in the conduit,which comprises establishing openings at either side of the section,inserting valve members in the conduit through the openings to preventflow of fluid into the section, and after the section has been replacedor repaired, displacing the air from the section through one of saidopenings by varying the relationship of the valve member which wasinserted in the other opening so as to permit the fluid contents of theconduit to enter the section.

4. The method of isolating a section of a fluid containing conduit,whereby the section may be replaced or repaired, and subsequentlyre-establishing communication between the section and the remainder ofthe conduit without substantial dilution of the fluid in the conduit,which comprises establishing openings at either side of the section,inserting valve members in the conduit through the openings to preventflow of fluid into the section, and after the section has been replacedor repaired, providing an outlet for the air which is trapped in thesection and displacing the air from the section, and from the conduit,by actuating one of the said valve members so as to provide a flowpassage from the conduit into the section.

5. The method of isolating a section of a fluid containing conduit,whereby the section may be replaced or repaired, and subsequentlyre-establishing communication between the section and the remainder ofthe conduit without substantial dilution of the fluid in the conduit,which comprises establishing openings at either side of the section,inserting valve members in the conduit through the openings to preventflow of fluid into the section, and after the section has been replacedor repaired, forcing the air in the section to flow out through one ofthe openings by injecting a fluid, similar to the fluid contained in theremainder of the conduit, through the other open- TIMOTHY A. LARRY. EARLE. CHINE.

